Disposable delicate tissue retractor

ABSTRACT

A disposable self-retaining brain and delicate tissue retractor with interchangeable disposable blades. The retractor and blades are designed to be molded from a lightweight material such as a plastic. The blades may be made of various shapes and sizes and, in most instances, are designed to be coated with a strip of gauze like material to protect and prevent injury to the brain or other soft tissue.

United States Patent 1191 Lake 5] Oct. 23, 1973 DISPOSABLE DELICATE TISSUE 3,030,947 4/1962 Engelbert 128/20 x RETRACTOR 3,199,512 8/1965 Cavanaugh et al. 128/345 X 3,364,919 1/1968 Hunnicutt 128/20 Inventor: Peter Lake, 121 Palm Canyon 3,570,475 3/1971 Weinstein 1213/20 Dr., Palm Springs, Calif. 92262 1 22 F] d FOREIGN PATENTS OR APPLICATIONS 1 1970 339,072 4/1936 Italy 128/345 [21] Appl, No; 79,372 11,426 0/1901 Great Britain. 128/17 559,239 7/1957 Belgium 128/17 lll. 1286361122433; Primary Examiner xy.le L- Howe," 58 Field of Search 24/20 TT, 248 L, A'tomeyspensley and Lub'tz 24/255 SL, 255 TZ; 128/17, l8, 19, 20, 242,

243, 244, 341, 345 ABSTRACT V A disposable self-retaining brain and delicate tissue [56] References f retractor with interchangeable disposable blades. The UNITED STATES PATENTS retractor and blades are designed to be molded from a 2 233 5 4/1941 Jacques." 123/34] X lightweight material such as a plastic. The blades-may 447,761 3/1891 Clough 123/17 be made of 'various shapes and sizes and, in most in- 569,839 10/1896 Roeloffs 128/17 stances, are designed to be coated with astrip of 776,302 9 CrQCkett 1213/20 gauze like material to protect and prevent injury to v I 3 the brain or other soft tissue 2,083,573 6/1937 Morgan 128/345 X 1 2,717,592 9/1955 Swineheart 128/17 19 Claims, 17 Drawing Figures PATENTEDUCT 23 I975 SHEET 1% 3 1 N VEN TOR.

PMENTEDUBIZB I975 3.756310 sum 2 or 3 1 N VEN TOR.

PAIENIEnnmams armsmo SHEET 3 OF 3 P572? 4 [4/65 INVENTOR.

. .1 DISPOSABLE DELICATE TISSUE RETRACTOR BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to the field of surgical devices and more particularly to soft tissue retraction surgical devices.

2. Prior Art An important part of all surgical procedures is exposure of an adequate operative field. To do this, soft tissue must be retracted for prolonged periods. By way of example, in brain surgery, it is often necessary to incise through braintissue and retract it aside to reach for tumors or blood clots deep within the brain substance. Also, manyoperations are designed to elevate the brain from the floor of the skull by retraction in order to reach the blood vessels and structures beneath the brain. i

1 Existing brain retractors in current use are of .two types. There are bent metal retractors, somewhat similar in shape to the familiar tongue depressor, in general being bent to achieve more complicated shapes. Such instruments are held by hand and, therefore, require the surgeon to perform all other tasks with the remaining hand. These instruments are further limited by the fact that they retract only one lip or side of an incision at a time and, because they are hand-held, the pressure applied to the tissue, such as the brain, is variable with the delicacy and length of the operating procedure. In addition, they are relatively expensive, ranging in price from $3.00 to $25.00 for each retractor.

The second type of available retractor is the selfretaining type. These instruments are not hand-held and, therefore, leave free both hands of the surgeon to perform other operating tasks. However, these retractors are fabricated of metal, and as such are heavy and may damage the soft tissue simply by the weight alone unless fixed or supported in some way. For brain surgery they require fixation to the bone of the skull either by clamping, which may be unstable, or by drilling another hole into the skull andscrewing a fixation post intothe bone. These retraction devices, like the handheld retraction device described above, also retract only one lip or side of a wound; Their cost-ranges typically from about $300000 to $1,000.00 for each retractor. I

BRIEF SUMMARY OF THE INVENTION ther designed to minimize any trauma which brain or other delicate tissue may undergo with retraction.

Three specific embodiments of the present invention are described herein. All the embodiments are' designed to be molded of plastic and contain arms on which disposable blades of various designs may readily be mounted. The retractors contain means for adjusting and locking the retractor blade separation and are of sufficiently low weight so as to allow the resting of ing additional support.

The retractor is designed to havedisposable blades and to retract both sides of an incision in varying amounts depending on the operation requirements. By

having disposable blades of various sizes and shapes, the retractor maybe used as a soft tissue retractor for nearly any operation. ;In addition, one of the disposable blades may be replaced with a tooth blade or a hook which, by way of example, would hook to the skull at the edge of the opening .in the skull created for purposes of the operation. In this mannerthe other blade would provide support for the brain and retraction between the brain and the skull. t

For most operations, a strip of gauze-like material, (e.g., telfa") with adhesive on the reverse side is fastened to the soft tissueside of the retractor blades and overlaps the plastic border thereon by approximately one millimeter to protect the soft tissue and to assist in absorbing fluids that may be secreted as a result of the wound.

BRIEF DESCRIPTION 'OF DRAWINGS FIG. 1 is a perspective of the retractor of the present invention showing the locking device, the retractable blades and the telfa pads thereon.

FIG. 2 is a top viewof the retractor of FIG. 1 showing the locking means in greater detail and indicating two. of the many possible lock positions for the arms of the retractor.

FIG. 3 is a side view of the retractor of FIG. 1 showingadditional detail in its structure.

FIG. 4 is a view of the retractor looking into the end of the retractor arms with the arms set so as to achieve the minimum retractor blade spacing.

FIG. 5 is a cross-sectional view of part of the retractor of FIG. 1 showing greater detail in the locking mechanism for the retractor arms.

FIG. 6 is an end view of one of the retractor arms end blade showing an alternate shape for a disposable blade and the location of the pad of gauze-like material on the blade.

FIG. 7 is a side viewof the blade and arm of FIG. 6 illustrating the overlap of the gauze-like pad with respect to the interchangeable blade.

FIG. 8 is a sketch illustrating the: use of the retractor of FIG. 1 to retract or separate the walls of an incision in brain tissue to enable the brain surgeon to reach tumors or blood clots deep within the brain substance.

FIG. 9 is a perspective view of a hook which may be used in place of one of the interchangeable blades of the retractor of FIG. 1.

FIG. 10 is a sketch illustrating the use of the retractor with the hook of FIG. 9, whereby the hook engages the skull at the edge of the skull opening and the blade of the retractor elevatesthe brain away from the base of the skull so that the surgeon may reach blood vessels and structures in that area. v

FIG. 11 is a top view of an alternate embodiment of the present invention, showing an alternate configura- FIG. 14 is a perspective view of a preferred embodiment with the locking members snapped together in functional disposition.

FIG. 15 is a perspective view of the preferred embodiment of the present invention as it would be molded of plastic.

FIG. 16 is a side view of the present invention soft tis sue retractor of FIG. 15.

FIG. 17 is a cross-sectional view of the preferred embodiment of the soft tissue retractor taken along lines 17-l7 of FIG. 15, showing the manner in which the locking members are retained in functional relationship to each other.

DETAILED DESCRIPTION OF THE INVENTION The invention to be presently described in detail is a disposable, self-retaining brain and delicate tissue retractor fitted with interchangeabledisposable blades lined with a disposable protective coating. This retractor is designed to be low cost, light in weight and to enable the surgeon to have both hands free to perform other tasks in the operation. The retractor is designed to minimize any trauma which brain or other delicate tissue may undergo upon retraction, and is further designed to retract both sides of an incision in soft tissue, or to elevate soft tissue away from bone structure.

Now referring to FIG. 1, a perspective view of one embodiment of the present invention soft tissue retractor may be seen. This embodiment of the retractor is comprised of the assembly of four separate molded parts. These parts are a molded ring 10 with retractor blade arms 12, two interchangeable disposable retractor blades 14, each of which slides into a mating groove in the ends of the retractor blade arms, and a locking member 16 which locks ring member 10 so as to achieve the desired separation in retractor blades 14. The retractor blade arms 12 each contain finger grips 18, which the surgeon may use to vary the separation in the retractor blades 14 prior to locking the retractor blades in position by locking member 16. Also, illus :trated in FIG. 1 are the disposable protective covering 20 of the retractor blades, which are generally used on the retractor of the present invention.

Now referring to FIG. 2, additional details of the retractor may be seen. Retractor ring 10 contains a tongue member 30 which extends into the opening between members 32. Tongue member 30 has a plurality of holes 34 generally disposed in a radial direction of ring 10 and equally spaced about the circular arc of tongue 30. Members 32 also contain a plurality of holes 36 generally directed in a radial direction of ring 10, and disposed in a circumferential direction with the same spacing of holes 34 in tongue member 30.

Locking member 40 contains locking pins 42 which have the same spacing as holes 34 and 36 of members 30 and 32 respectively. Therefore, locking pins 42 may be inserted into holes 34 and 36 when some holes 34 of tongue member 30 are in line with the holes 36 in members 32 as shown in the cutaway sketch of FIG. 5. When so positioned, the-locking pins 42 lock tongue member 30 with respect to members 32, thereby locking retractor arms 12 at a specific separation and more importantly, lock interchangeable retractor blades 14 at a fixed separation.

In the embodiment shown, locking member 40 contains three locking pins 42 and members 32 contain three sets of holes 36 whereas tongue member 30 conains a plurality of holes substantially exceeding three in number, so that three holes of tongue member 30 will align with the holes 36 in members 32 for various separations of retractable blades 14, thereby allowing the locking of the blades 14 by locking member 40 at various distances of separation.

' Shown in phantom of FIG. 2 is the position of the retractor arms 12 for minimum separation of the retractor blades 14. It may be seen that the retractor arms 12 do not come together in this position, but are disposed in a substantially parallel position with a substantial separation therebetween. However, the retractor blades 14 are substantially in contact when the retractor arms 12 are so located. This is well illustrated in FIG. 4 where it may be seen that because of the angle or bend 44 in the retractor blades 14, a-large portion of the retractor blades 14 generally, indicated by the numeral 46, is in contact with or in close proximity to the other retractor blade. Also illustrated in FIG. 4 is the separation in the retractor arms 12 when the retractor blades 14 are in close'proximity as just described.

FIG. 4 furtherillustrates the use of the telfa pads 50 on the outer surfaces of the retractor blades. It may be seen that in general the gauze-like pads 50 will extend from approximately the angle 44 in the retractor blades 14 to slightly beyond the lower edge of the retractor blades 14, so as to provide an overlap of padding 52 to curve around the lower end of the retractor blades and to prevent damage to tissue by the end of the blades. The pad 50 also extends in a direction parallel to the retractor arms 12 so as to slightly overlap the edges of the retractor blades 14 again for the purposes of pre- '-venting injury to the tissue by the edges of the retractor blades 14. This may be seen generally in FIGS. 1, 2, 3, 7 and 12, generally indicated by the numeral 52. In the preferred embodiment, pad 50 would be provided with an adhesive backing so that it would naturally adhere to the surfaces of the retractor blades 14 in the desired position. In alternative embodiments, pad 50 might be in the shape of an envelope so as to substantially fully enclose the lower portion of the retractor blades 14, fully protecting the wound from contact with retractor blades 14 and perhaps retain in position on the retractor blades by adhesive backing, appropriately placed.

Referring to FIG. 3, a side view of the retractor of FIG. I'may be seen. This figure illustrates the generally planar character of ring 10 and retractor arms 12 and the nature of the protrusion which forms the finger grips 18. Also shown in this figure is the generally overlapping nature of telfa pad 50 at the edges of the retractor blade 14 indicated generally by the areas 54 of the telfa pad. In general, the underside of arms 12 and ring 10, generally indicated by surface 60, will rest on and be supported by an area of the body surrounding the incision in which retractor blades 14 have been inserted. The generally planar character of retractor arms 12 and ring 10 is suitable for most operations and, therefore, constitutes the form of the preferred embodiment. However, it is to be understood that arms 12 and ring 10 can be given other shapes so as to generally conform to the contours of the areas of the body and operations being performed.

FIG.6 shows an alternate shape for retractor blade 14. This blade is similar in shape to the blades shown in FIG. 4 but does not have the angle 44. Such a blade might be used in conjunction with the retractor of FIG. 1 to provide a wider retraction at the mouth of the incision than at the base of the incision. At a further alternative, the slots in the end of the retractor arms 12 in which the retractor blades 14 fit may be substantially vertical when viewed as shown in FIG. 4, rather than inclined as shown in that FIG. In such a case, retractor blades such as those shown in FIG. 6 would project substantially parallel to each other when mounted to the retractor arms 12 and would allow locking of the retractor blades at greater separations than possible with the configuration of FIG. 4, though such blades would have a substantially greater minimum separation than is possible with the configuration of FIG. 4. It is to be understood that the details of the manner in which retractor blades 14 are attached to the retractor arms 12 may be varied without departing from the spirit and scope of the present invention. Similarly, the blades themselves may be varied so as to be adapted for use in various surgical procedures. By way of example, in the preferred embodiment, interchangeable retractor blades of various lengths, widths, angles, offsets or curvatures would be made available for use with the same retractor, so as to make that retractor useful in many varied types of operation. In general, the retractor blades and the retractor body would be sold independently in presterilized packages so that only the package containing the desired blades need be opened for a specific operation, and only those blades and the retractor body need be disposed of after the operation.

FIG. 7 is a side view of the retractor arm 12 with a retractor blade 14 mounted thereon and a telfa pad 50 attached to the retractor blade. It may be seen that the pad 50 is somewhat larger than the retractor blade 14 so as to overlap both the edges 54 and the bottom 52 of the retractor blade 14, presenting to the wound a fully padded and protected retractor blade.

FIG. 8 is. a sketch illustrating the use of the present invention, retractor in brain surgery. As shown in the F IG., the brain is exposed by drilling six holes 60 in the skull and slicing the skull so as to interconnect the holes 60 to make removeable an area of the skull 64 defined by the holes. A portion of the scalp between two holes is not severed so that the removeable portion of the scalp 64 may be pivoted on the flap the brain scalp 66 and made to rest on an adjacent area of the head to expose the desired area. This exposes the dura mater which envelopes the brain and is external to the arachnoid and pia mater. In such an operation it is often necmember 40 may then be inserted so as to lock the ring 12 in a fixed'position so that finger pressure is no longer required on finger grips 18 to maintain the desired separation in retractor blades 14. Although ring member 10 may only be locked in certain specific positions, a sufficient number of locked positions may be provided by the plurality of holes 30 (FIG. 2) so as to achieve substantially all desired retractor settings. Also, it is to be understood that means for locking the retractor other than that shown in detail in FIGS. 2 and 5 may be provided. By way of example, member 40 might be designed to have only one or two locking pins 42 and members 32 might have a plurality of holes 36 equal in number to one more or one less than the number of holes in tongue member 30, thereby providing a vernier adjustment or selection of the retractor blade spacing by inserting locking member 40 into one of the possible hole combinations. This and other locking means may readily be adapted for use with the retractor of the present invention by anyone skilled in the mechanical arts.

The retractor of the present invention is sufficiently light in weight that'it requires no fixation to the body of the patient, other than that which naturally arises from the location of the retractor blade in the incision while the soft tissue is retracted. Furthermore, the retractor need not rest on or be supported by bone structure. By way of example, as shown in FIG. 8, the retractor may rest upon and be supported by the dura covering the brain without fear of injury to either the dura or the brain structure thereunder. Therefore, separate holes in the skull for purposes of anchoring the retractor are not required, nor is the surgeon required to use one hand for operating the retractor once the retractor is properly set. Furthermore, since the retractor may rest on the dura, the retractor physically may be relatively small and, therefore, need not needlessly encumber the operating area.

In some operations it is necessary to elevate the brain from the floor of the skull by retraction in order to reach the blood vessels and structures beneath the brain. For such purposes, one of the retractor blades may be configured as a hook-like member as shown in FIG. 9. (Though the blades heretofore described have been substantially fiat blades, the term blade as used herein is used in the general sense to include, by way of, example, blades of various shapes and curvatures,

essary to incise through brain tissue and retract it aside to reach for tumors or blood clots deep within the brain substance. To do this an incision is first made and then the retractor of the present invention is used to separate the brain tissue at the incision so as to make accessable tissue deep within thebrain substance. The retractor may be put in place by removing locking member 40, squeezing on finger grips 18 so as to bring the retractor blades 14 into close proximity as shown in FIG. 4, and inserting the retractor 14 into the incision. Because the retractor blades 14 are interchangeable, the size and shape of the blade may be selected depending on the requirements of the particular operation and the nature of the incision which has been made. Once the blades are inserted in the incision, the brain tissue may be retracted by lessening the pressure applied to the finger grips 18', thereby allowing ring 10 to partially spring open forcing retractor blades 14 to move away from each other and to open the incision made in the brain. When the desired opening is obtained, locking and to include hooks and hook members, as are about to be described herein.) In this figure, hook member contains hook 72 and mounting surfaces 74 which make it interchangeable with the blades 14 of the retractor variously depicted in FIGS. 1 through 8. Hook member 70 may be used in conjunction with one of the retractor blades 14 in a retractor to elevate the brain as shown in FIG. 10. In this figure, as opening has been made in the side of the skull so as to provide access to the base of the brain. Retractor blade 14 is then inserted beneath the brain 76 with hook members 70 hooking over the edge of the opening in the skull 78, thereby allowing retraction of the brain 76 with respect to the skull 78 to lift the brain from the base of the skull 78 and provide access to the floor of the skull in order to reach the blood vessels and other structures there located. 7 1

FIGS. 11 and 12 present a top view and a side view of an alternate embodiment of the present invention. In this embodiment, the retractor blades 14 may be sub- 7 stantially the same as the retractor blades in the embodiment pictured in FIG. 1. As in that embodiment, the blades of the embodiment shown in FIGS. 11 and 12 are also removeable and blades or hooks of various designs may readily be slipped in place in the ends of retractor arms 80. The retractor arms of this embodiment form a basic V shape with the structure in the vicinity of the apex of the V providing the required elasticity to encourage the retractor arms 80 to a fully separated position. Finger grips 82 are similar in function to finger grips 18 of the embodiment shown in FIG. 1, and provide a means for changing the separation of the retractor blades 14.

Locking member 84 may be used to lock the retractor blades 14 at various separations by the placement of lock 84 at any of a plurality of possible positions along the retractor arms 80. Locking member 84 is shown in FIG. 11 in a position to lock the retractor arms 80 in the position for maximum retractor blade 14 spacing. Shown in phantom in that figure is an alternate location for locking member 84, which locks retractor arms in a position for a smaller retractor blade spacing. Additional retractor blade spacings may be obtained either by providing more numerous positions for locking member 84 or by providing a selection of locking members 84 which may be used so as to achieve virtually any desired retractor blade 14 spacing.

FIG. 13 presents a cross-section of the retractor of FIGS. 11 and 12 taken on lines 13-13 of FIG. 12. This cross-section shows further details in the structure of locking member 84 and of retractor arms 80 in the regions of the various locking member positions. Retractor arms 80 have a generally circular cross-section in the locking area with V notches 86 in each arm 80 disposed in a generally outward facing direction. Locking member 84 contains hook-like projections 88 which, when in position, retain arms 80 with respect to locking member 84. By applying pressure on finger grips 82 (FIG. 11), the retractor arms 80 may be encouraged into closer proximity to each other, thereby allowing the removal or change of locking member 84 to a new locking position. Further integrity in the locking action between locking member 84 and the retractor arms 80 is provided by the contouring of the inner surface of locking member 84' so as to mate with the surfaces of notches 86 in the retractor arms 80.

Now referring to FIG. 14, a perspective view of a preferred embodiment of the present invention may be seen. This embodiment of the invention consists of body member 100 with two arms 102, extending therefrom in side by side relationship and each having a replaceable retractor blade 104 attached to the end thereof. The arrangement of arms 102 and the manner in which replaceable blades 104 attach thereto is the same as in the embodiments previously disclosed herein, particularly the embodiment shown in FIGS. 1 through 4. Body member 100 is in the form of a split ring having a flexible portion 106 between arms 102 and further having mating locking members 108 and 109 adjacent to the split in body member 100. As molded, the locking members 108 and 109 are disposed in a non-functional relation as shown in FIG. 15, and are subsequently elastically encouraged to the functional relationship shown in FIG. 14. In this position, the teeth 1070f the locking members 108 and 109 are elastically encouraged into engagement and, as a result of this engagement, provide a means of locking the-retractor blades 104 in the desired separation.

The body member is molded of plastic material in the shape shown in FIG. 15. As previously described, locking members 108 and 109 are disposed in a nonfunctional relationship but body member 100 is intentionally designed and fabricated to have sufficient elastic properties so that locking members 108 and 109 may be elastically deformed to their functional disposition shown in FIG. 14. It is to be also noted in FIG. 15 that body member 100 is molded with arms 102 in a substantially converging orientation so that when retractor blades 104 are mounted thereto, as was shown in FIG. 4 for the retractor blades 14 pictured therein, the arms 102 are elastically urged into substantially a parallel relationship. In this manner, the elastic area 106 between arms 102 is elastically encouraging retractor blades 104 into closer proximity to each other even for little or substantially no initial retractor blade separation. Of course, as the soft tissue retractor is normally disposed in an incision in soft tissue, the normal pressure of the soft tissue on retractor blades 104 also encourages the retractor blades into lesser separation. Consequently, locking members 108 and 109 need not provide a bilateral locking action, but need only provide a unilateral action so as to prevent retractor blades 104 from moving into lesser separations. To accomplish this, the teeth 107 of the locking members 108 and 109 are inclined in the manner shown in FIGS. 14 and 15 so that they provide the desired unilateral locking action but are free to slip over each other in the opposite direction to adjust to and lock retractor blades 104 at greater separations.

Body member 100 contains finger grips 110 which extend upward from body member 100. By applying finger pressure betweenthese finger grips 100, the retractor blades 104 may be moved into greater distances of separation and locked at any of a number of separations by the action of the teeth 107 on locking members 108 and 109. Also protruding upward are the release fingers 112, one of which extends upward from the end of a locking member 108 and the other from the end of locking member 109. To release thelocking members 108 and 109 so that retractor blades 104 may be moved to lesser separations, finger pressure may be applied to the release fingers 112 so as to elasticallyencourage locking members 108 and 109 into separation, thereby allowing the translation of the locking members with respect to each other in a direction normally' prevented by the engagement of the teeth thereof.

Now referring to FIG. 16, a side view of this preferred embodiment of the present invention soft tissue retractor may be seen. As was previously described in regard to previously disclosed embodiments, body member 100 is a substantially flat member with the only substantial downward protrusions being the replaceable retractor blades 104. Since the soft tissue retractor will normally be molded of a light weight material and in particular a light weight plastic material, the substantially flat bottom surface of body member 100 allows the soft tissue retractor to lie flat on an area of the body adjacent to the incision without additional anchoring or support. Also shown in this figure are the finger grips 110 and the release fingers 112, which are the only substantial protrusions above the top surface of body member 100, thereby providing a minimum of obstruction and encumbrance of the operating region.

Now referring to FIG. 17, a cross-section of locking members 108 taken along lines 17-17 of FIG. may be seen. In this figure, it may be seen that locking members 108 and 109 have mating toothed surfaces substantially in the form of a tongue and groove with the teeth 107 located on the end of the tongue and inthe bottom of the groove. This arrangement tends to retain locking members 108 and 109 in functional disposition and to prevent their lateral displacement and return to the molded position shown in FIG. 15, particularly with finger pressure is applied to finger grips 110 or release fingers 112.

In this last embodiment, which is the preferred=embodiment, the body member 100 elastically encourages retractor blades 104 to lesser separations and the locking members 108 and 109 act to prevent the movement of retractor blades 104 to such lesser separations. In this manner, any slippage or failure of the locking members 108 and 109 result in the movement of the retractorblades 104 to lesser separations, that is, to the closed position, as a result of both the elastic deflection of the elastic member 106 and the normal pressure that the wound would apply to the retractor blades 104. This movement, that is the movement of the retractor blades so as to close the wound, upon the unlikely occurrence of the failure in the locking member 108 and 109 to properly perform, would in most operations be the desired occurrence. This is in contrast to the characteristics of the two specific embodiments previously described, both of which are elastically encouraged to the open position, that is to greater separations of the retractor blades 104, should a malfunction of the locking mechanism occur.

The soft tissue retractor of the present invention reduces the trauma experienced during the operation over that experienced by using the prior art retractors.

. In addition to the trauma reducing effect of the gauze pads, the more equal distribution of pressure around the incision, because of equal retraction on both sides of the incision rather than the unilateral retraction characteristic of the prior art retractors, has a substantial trauma reducing effect. Also, it is easier to periodically loosen the present invention retractor during the operation which also has a trauma reducing effect.

The soft tissue retractor of the presnt invention may be molded of any of a number of plastics, since many plastics have sufficient strength and elasticity for such purposes and yet are sufficiently light to yield a durable and useful soft tissue retractor which doesnot require anchoring or support. Though a plastic having the capability of maintaining its properties when immersed in boiling water would allow sterilization of the soft tissue retractor in boiling water, such a temperature capability in the plastic used is not required, as other means of sterilization are commonly used for such equipment. By way of example, plastic forceps and other instruments are commonly sterilized in an ethylene oxide atmosphere at normal temperatures, thereby providing adequate sterilization without temperature elevation. Consequently, plastic such as polypropylene and polyethylene are suitable for such purposes because of their light weight, moldability, strength and physical integrity. Also of particular interest for use in the present invention is polystyrene, which though havng a relatively low heat resistance, is an inexpensive material which is easily molded and readily sterilized in an oxidizing atmosphere.

It is to be understoodthatthethree embodiments of the present invention described herein in detail are presentedmerely for purposes of illustration, and having now described the details of these embodiments, one skilled in the art of surgical devicescould readily construct soft tissue retractors of otherdesigns having theinvented features of theherein described soft tissue retractorsrBy way of examplegflexible member 106 in FIGS. 14 and 15 might be replacedbya pivot, thereby making body member into twopieces and allowing the pressure of the softtissue to encourage retractor blades 104 .into lesser separations should the locking device fail to properlyperform. Similarly, body member 100, whether one piece or two as just described, might be curved, bent or have other shapes substantially different from the flat ring like shape shown in FIG. 14 and FIG. 15. Also various otherlocking devices may be .used inplace of the locking devices disclosed herein. These and other variations of the present invention may become particularly useful in specific types of operations wherein a specific configuration or specific locking method is particularly desired.

Iclaim:

l. A soft tissue retractor comprised of blades, a body member and a locking means,

said body member having first and second end re gions and being curved so as to enclose an area, with said first and second end regions adjacently disposedinoverlapping relationship with respect to each other, said body member including integral therewith two adjacent generally coplanar elongated members extending therefrom generally in theplane of said body member, and extending from one side of said body member;

said elongated members each supporting one of said blades near the outer end of said elongated member;

said blades being disposed in a plane substantially normal to the longitudinal axis of said elongated members and adapted to retract soft tissue;

said locking means including means to retain said i first and second end regions in any of a plurality of relative dispositions whereby said blades may be retained at any of a selection of separations.

2. The retractor of claim 1 whereinsaid body member further includes two finger grips extending from whereby finger pressure may be applied to said finger grips to encourage said blades to different separations.

3. The retractor of claim 1 wherein said locking means includes a separate member adapted to engage with said end regions.

4. The retractor of claim 1 wherein said blades are detachable from said elongated members and said blades and said elongated members. contain mating surfaces, said mating surfaces being adapted to allow said blades and said elongated members to be pushed together and retained, one to the other.

5. The retractor of claim 1 wherein one blade includes at least one hook-like protrusion to locate with respect to bone structure.

6. The retractor of claim 1 further comprised of gauze-like pads on said blades, said gauze-like pads having an adhesive backing to adhere to said blades, wherein said gauze-like pads substantially fully surround the portion of each of said blades which is adapted to retract soft tissue, said pads being constructed in the form of an envelope and being open only at one edge to facilitate the placement of said pads on the blades and to allow the protrusion of the portion of said blades that connects with said elongated members.

7. The retractor of claim 1 wherein said retractor is constructed of plastic.

8. The retractor of claim 1 wherein said body member has cooperatively disposed toothed regions adjacent its said ends and means for elastically encouraging said toothed regions to mate to retain said blades at any of a selection of separations.

9. A soft tissue retractor comprised of two blades, a body member and a locking means,

said body member being a ring member having two adjacent generally coplanar elongated members extending therefrom generally in the plane of said body member, and extending from one side of said body member; I

said elongated members each supporting one of said blades near the outer end of said elongated member;

said blades being disposed in a plane substantially normal to the longitudinal axis of said elongated members and adapted to retract soft tissue;

said ring member having a tongue member forming a portion of the arc of said ring member and extending between two mating members of said ring member;

said mating members also forming a portion of the arc of said ring member;

said tongue member and said mating members each having a plurality of holes therein;

said holes being disposed so as to form at least one continuous hole through said tongue member and said mating members at a plurality of separations of said blades;

said locking means including at least one pin member, said pin member being adapted for insertion into a continuous hole-through said tongue member and said mating members to lock said blades at any of said plurality of separations.

10. The retractor of claim 9 wherein said body member elastically encourages said blades to greater separations, said body member further including two fingers grips extending therefrom whereby finger pressure may be applied to said finger grips to encourage said blades to smaller separations.

11. A soft tissue retractor comprised of two blades and a body member,

said body member having first and second ends and being curved so as to enclose an area with its ends overlapping, said body member having two adjacent generally coplanar elongated members extending therefrom generally in the plane of said body member, and extending from one side of said body member;

said elongated members each supporting one of said blades near the outer end of said elongated members;

said blades being disposed in a plane substantially normaljto the longitudinal axes of said elongated members and adapted to retract soft tissue;

said body member having cooperatively disposed toothed regions adjacent its said ends, and means for elastically encouraging said toothed regions to mate to retain said blades at any of a selection of separations.

12. The soft tissue retractor of claim 11 wherein said teeth are inclined to provide means to allow movement of said retractor blades to greater separations and to prevent substantial movement of said retractor blades to lesser separations without elastically and separately forcing said toothed regions out of engagement.

13. The retractor of claim 11 wherein said body member further includes two extending finger grips whereby finger pressure may be applied to said finger grips to encourage said blades to increased separations.

14. The retractor of claim 11 wherein said body member further includes two extending release grips whereby finger pressure may be applied to said release grips to encourage said toothed regions into separation.

15. The retractor of claim 11 wherein the portion of said body member between said elongated arms comprises means elastically encouraging said retractor blades to lesser separations.

16. The retractor of claim 11 wherein said blades are detachable from said elongated members and said blades and said elongated members contain mating surfaces, said mating surfaces being adapted to allow said blades and said elongated members to be pushed together and retained, one to the other.

17. The retractor of claim 11 wherein one blade includes at least one hook-like protrusion to locate with respect to bone structure.

18. The retractor of claim 11 further comprised of gauze-like pads on said blades, said gauze-like pads having an adhesive backing to adhere to said blades, wherein said gauze-like pads substantially fully surround the portion of each of said blades which is adapted to retract soft tissue, said pads being constructed in the form of an envelope and being open only at one end to facilitate the placement of said pads on the blades and to allow the protrusion of the portion of said blades that connects with said elongated members.

19. The retractor of claim 11 wherein said retractor is constructed of plastic. 

1. A soft tissue retractor comprised of blades, a body member and a locking means, said body member having first and second end regions and being curved so as to enclose an area, with said first and second end regions adjacently disposed in overlapping relationship with respect to each other, said body member including integral therewith two adjacent generally coplanar elongated members extending therefrom generally in the plane of said body member, and extending from one side of said body member; said elongated members each supporting one of said blades near the outer end of said elongated member; said blades being disposed in a plane substantially normal to the longitudinal axis of said elongated members and adapted to retract soft tissue; said locking means including means to retain said first and second end regions in any of a plurality of relative dispositions whereby said blades may be retained at any of a selection of separations.
 2. The retractor of claim 1 wherein said body member further includes two finger grips extending from whereby finger pressure may be applied to said finger grips to encourage said blades to different separations.
 3. The retractor of claim 1 wherein said locking means includes a separate member adapted to engage with said end regions.
 4. The retractor of claim 1 wherein said blades are detachable from said elongated members and said blades and said elongated members contain mating surfaces, said mating surfaces being adapted to allow said blades and said elongated members to be pushed together and retained, one to the other.
 5. The retractor of claim 1 wherein one blade includes at least one hook-like protrusion to locate with respect to bone structure.
 6. The retractor of claim 1 further comprised of gauze-like pads on said blades, said gauze-like pads having an adhesive backing to adhere to said blades, wherein said gauze-like pads substantially fully surround the portion of each of said blades which is adapted to retract soft tissue, said pads being constructed in the form of an envelope and being open only at one edge to facilitate the placement of said pads on the blades and to allow the protrusion of The portion of said blades that connects with said elongated members.
 7. The retractor of claim 1 wherein said retractor is constructed of plastic.
 8. The retractor of claim 1 wherein said body member has cooperatively disposed toothed regions adjacent its said ends and means for elastically encouraging said toothed regions to mate to retain said blades at any of a selection of separations.
 9. A soft tissue retractor comprised of two blades, a body member and a locking means, said body member being a ring member having two adjacent generally coplanar elongated members extending therefrom generally in the plane of said body member, and extending from one side of said body member; said elongated members each supporting one of said blades near the outer end of said elongated member; said blades being disposed in a plane substantially normal to the longitudinal axis of said elongated members and adapted to retract soft tissue; said ring member having a tongue member forming a portion of the arc of said ring member and extending between two mating members of said ring member; said mating members also forming a portion of the arc of said ring member; said tongue member and said mating members each having a plurality of holes therein; said holes being disposed so as to form at least one continuous hole through said tongue member and said mating members at a plurality of separations of said blades; said locking means including at least one pin member, said pin member being adapted for insertion into a continuous hole through said tongue member and said mating members to lock said blades at any of said plurality of separations.
 10. The retractor of claim 9 wherein said body member elastically encourages said blades to greater separations, said body member further including two fingers grips extending therefrom whereby finger pressure may be applied to said finger grips to encourage said blades to smaller separations.
 11. A soft tissue retractor comprised of two blades and a body member, said body member having first and second ends and being curved so as to enclose an area with its ends overlapping, said body member having two adjacent generally coplanar elongated members extending therefrom generally in the plane of said body member, and extending from one side of said body member; said elongated members each supporting one of said blades near the outer end of said elongated members; said blades being disposed in a plane substantially normal to the longitudinal axes of said elongated members and adapted to retract soft tissue; said body member having cooperatively disposed toothed regions adjacent its said ends, and means for elastically encouraging said toothed regions to mate to retain said blades at any of a selection of separations.
 12. The soft tissue retractor of claim 11 wherein said teeth are inclined to provide means to allow movement of said retractor blades to greater separations and to prevent substantial movement of said retractor blades to lesser separations without elastically and separately forcing said toothed regions out of engagement.
 13. The retractor of claim 11 wherein said body member further includes two extending finger grips whereby finger pressure may be applied to said finger grips to encourage said blades to increased separations.
 14. The retractor of claim 11 wherein said body member further includes two extending release grips whereby finger pressure may be applied to said release grips to encourage said toothed regions into separation.
 15. The retractor of claim 11 wherein the portion of said body member between said elongated arms comprises means elastically encouraging said retractor blades to lesser separations.
 16. The retractor of claim 11 wherein said blades are detachable from said elongated members and said blades and said elongated members contain mating surfaces, said mating surfaces being adapted to allow said blades and said elongated members tO be pushed together and retained, one to the other.
 17. The retractor of claim 11 wherein one blade include at least one hook-like protrusion to locate with respect to bone structure.
 18. The retractor of claim 11 further comprised of gauze-like pads on said blades, said gauze-like pads having an adhesive backing to adhere to said blades, wherein said gauze-like pads substantially fully surround the portion of each of said blades which is adapted to retract soft tissue, said pads being constructed in the form of an envelope and being open only at one end to facilitate the placement of said pads on the blades and to allow the protrusion of the portion of said blades that connects with said elongated members.
 19. The retractor of claim 11 wherein said retractor is constructed of plastic. 